Deformations and electromagnetic moments in carbon and neon isotopes

Static and dynamic quadrupole moments of C and Ne isotopes are investigated by using the deformed Skyrme Hartree-Fock model and also shell model wave functions with isospin-dependent core polarization charges. We point out that the deformations of C and Ne isotopes have a strong isotope dependence as a manifestation of spontaneous symmetry breaking effect in nuclear physics. The effect of spontaneous symmetry breaking is a general phenomenon known in many fields of physics. It is shown at the same time that the quadrupole moments Q and the magnetic moments μ of the odd C and odd Ne isotopes depend clearly on assigned configurations, and their experimental data will be useful to determine the deformations of the ground states of nuclei near the neutron drip line. Electric quadrupole (E2) transitions in even C and Ne isotopes are also studied using the polarization charges obtained by the particle vibration coupling model with shell model wave functions. Although the observed isotope dependence of the E2 transition strength is reproduced properly in both C and Ne isotopes, the calculated strength overestimates an extremely small observed value in ¹⁶C.